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Fallica AN, Pittalà V, Modica MN, Salerno L, Romeo G, Marrazzo A, Helal MA, Intagliata S. Recent Advances in the Development of Sigma Receptor Ligands as Cytotoxic Agents: A Medicinal Chemistry Perspective. J Med Chem 2021; 64:7926-7962. [PMID: 34076441 PMCID: PMC8279423 DOI: 10.1021/acs.jmedchem.0c02265] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
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Since their discovery
as distinct receptor proteins, the specific
physiopathological role of sigma receptors (σRs) has been deeply
investigated. It has been reported that these proteins, classified
into two subtypes indicated as σ1 and σ2, might play a pivotal role in cancer growth, cell proliferation,
and tumor aggressiveness. As a result, the development of selective
σR ligands with potential antitumor properties attracted significant
attention as an emerging theme in cancer research. This perspective
deals with the recent advances of σR ligands as novel cytotoxic
agents, covering articles published between 2010 and 2020. An up-to-date
description of the medicinal chemistry of selective σ1R and σ2R ligands with antiproliferative and cytotoxic
activities has been provided, including major pharmacophore models
and comprehensive structure–activity relationships for each
main class of σR ligands.
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Affiliation(s)
- Antonino N Fallica
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Valeria Pittalà
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Maria N Modica
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Loredana Salerno
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Romeo
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Agostino Marrazzo
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Mohamed A Helal
- University of Science and Technology, Biomedical Sciences Program, Zewail City of Science and Technology, October Gardens, sixth of October, Giza 12578, Egypt.,Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Sebastiano Intagliata
- Department of Drug and Health Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
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Dey R, Bishayi B. Ciprofloxacin and dexamethasone in combination attenuate S. aureus induced brain abscess via neuroendocrine-immune interaction of TLR-2 and glucocorticoid receptor leading to behavioral improvement. Int Immunopharmacol 2021; 97:107695. [PMID: 33962227 DOI: 10.1016/j.intimp.2021.107695] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/06/2021] [Accepted: 04/18/2021] [Indexed: 12/14/2022]
Abstract
Staphylococcus aureus induced brain abscess is a critical health concern throughout the developing world. The conventional surgical intervention could not regulate the abscess-induced brain inflammation. Thus further study over the alternative therapeutic strategy for treating a brain abscess is of high priority. The resident glial cells recognize the invading S. aureus by their cell surface Toll-like receptor-2 (TLR-2). Glucocorticoid receptor (GR) was known for its immunosuppressive effects. In this study, an attempt had been taken to utilize the functional relationship or cross-talking between TLR-2 and GR during the pathogenesis of brain abscesses. Here, the combination of an antibiotic (i.e. ciprofloxacin) and dexamethasone was used to regulate the brain inflammation either in TLR-2 or GR blocking condition. We were also interested to figure out the possible impact of alternative therapy on behavioral impairments. The results indicated that combination treatment during TLR-2 blockade significantly reduced the bacterial burden and abscess area score in the infected brain. However, marked improvements were observed in anxiety, depression-like behavior, and motor co-ordination. The combination treatment after TLR-2 blocking effectively scavenged free radicals (H2O2, superoxide anion, and NO) through modulating antioxidant enzyme activities that ultimately control S. aureus induced glial reactivity possibly via up-regulating GR expression. The exogenous dexamethasone might regulate the GR expression in the brain by increasing the corticosterone concentration and the GC-GR mediated signaling. Therefore, this in-vivo study demonstrates the possible regulatory mechanism of bacterial brain abscess that involved TLR-2 and GR as a part of neuroendocrine-immune interaction.
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Affiliation(s)
- Rajen Dey
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, Calcutta, West Bengal, India
| | - Biswadev Bishayi
- Department of Physiology, Immunology Laboratory, University of Calcutta, University Colleges of Science and Technology, Calcutta, West Bengal, India.
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3
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Matsubara Y, Okuda H, Harada KH, Youssefian S, Koizumi A. Mechanical allodynia triggered by cold exposure in mice with the Scn11a p.R222S mutation: a novel model of drug therapy for neuropathic pain related to Na V1.9. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2021; 394:299-306. [PMID: 32970203 PMCID: PMC7835175 DOI: 10.1007/s00210-020-01978-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022]
Abstract
Mutations within the SCN11A gene which encodes the voltage-gated sodium channel NaV1.9 mainly expressed in small fiber sensory neurons have been associated with neuropathic disorders; however, suitable medications have not been fully investigated. To develop drug therapies against NaV1.9-related neuropathic pain, we aimed to establish a novel model using mice carrying the Scn11a p.R222S mutation initially identified in patients with familial episodic limb pain that is characterized by paroxysmal pain induced by fatigue or bad weather conditions. We investigated the influence of cold exposure (4 °C, overnight) on the behavioral and biochemical phenotypes of Scn11a p.R222S mutant (R222S) and wild type C57BL/6N (WT) mice. We also tested the effects of acetaminophen (125, 250 mg/kg, perorally, p.o.) and traditional Japanese medicine, goshajinkigan (0.5 or 1.0 g/kg, p.o.), which are analgesic drugs prescribed to patients with neuropathic pain, in this model of cold-induced mechanical allodynia in R222S mice.Cold-exposed R222S mice exhibited enhanced mechanical allodynia and thermal hypersensitivity compared with WT mice. The decrease of the mechanical withdrawal threshold in R222S mice was reversible 24 h after housing at room temperature. There was no significant change in the levels of interleukin-1β, interleukin-6, tumor necrosis factor-α, or interferon-γ in the plasma or spinal cords of WT and R222S mice after cold exposure. Both acetaminophen (250 mg/kg) and goshajinkigan (1.0 g/kg) significantly attenuated mechanical allodynia in R222S mice. The model of cold-induced mechanical allodynia in mice with the Scn11a p.R222S mutation is novel and useful for evaluating analgesic drugs for intractable neuropathies related to NaV1.9.
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Affiliation(s)
- Yosuke Matsubara
- Tsumura Kampo Research Laboratories, Tsumura & Co., Ibaraki, Japan.
- Laboratory of Molecular Biosciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
| | - Hiroko Okuda
- Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kouji H Harada
- Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shohab Youssefian
- Laboratory of Molecular Biosciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akio Koizumi
- Department of Health and Environmental Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Social Health Medicine Welfare Laboratory, Public Interest Incorporated Association Kyoto Hokenkai, Kyoto, Japan
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Mazeto TK, Picada JN, Correa ÁP, Rebelo IN, Ribeiro MT, Gomez MV, de Souza AH. Antinociceptive and genotoxic assessments of the antagonist TRPV1 receptor SB-366791 on morphine-induced tolerance in mice. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2020; 393:481-490. [PMID: 31655852 DOI: 10.1007/s00210-019-01748-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/09/2019] [Indexed: 12/17/2022]
Abstract
Chronic pain is mainly treated with opioid analgesics such as morphine. However, the use of these substances can cause adverse effects, including dependence and tolerance, necessitating the discovery of a new approach to analgesic therapies. The transient receptor potential vanilloid 1 (TRPV1) is linked to thermal sensibility and has been considered as a new therapeutic option for pain treatment. This study aims to investigate the antinociceptive effect and toxicity of SB-366791, a TRPV1 antagonist. Morphine-tolerant and morphine non-tolerant Swiss mice were submitted to the hot plate and thermal tail flick tests. Toxicological evaluations of the genotoxic and mutagenic activities of SB-366791 were assessed using a comet assay and micronucleus test, and the Salmonella/microsome mutagenicity assay. In the hot plate test, intrathecal injection of SB-366791 or morphine resulted in significantly increased antinociception in non-tolerant mice. SB-366791 also led to an analgesic effect in the tail flick test. Tolerant mice that received SB-366791 demonstrated a central antinociceptive effect in both thermal tests. No genotoxic effects were observed in the comet assay and no mutagenic effects were detected in the micronucleus test or in the Salmonella/microsome assay. Behavioral results of the thermal nociception tests show that SB-366791 has antinociceptive potential in both morphine-tolerant and non-tolerant mice and does not cause genotoxic or mutagenic effects. Nevertheless, new studies should be performed to clarify the activity and participation of vanilloid channels in the antinociception of SB-366791.
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Affiliation(s)
- Thiago Kastell Mazeto
- Graduate Program in Cellular and Molecular Biology Applied to Health Sciences, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Jaqueline Nascimento Picada
- Graduate Program in Cellular and Molecular Biology Applied to Health Sciences, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil.
- Graduate Program in Genetics and Applied Toxicology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil.
| | - Áurea Pandolfo Correa
- Department of Pharmacology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Isadora Nunes Rebelo
- Department of Pharmacology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Magali Terra Ribeiro
- Graduate Program in Genetics and Applied Toxicology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
| | - Marcus Vinícius Gomez
- Department of Neurotransmitters, Institute for Education and Research, Hospital Santa Casa, Domingos Vieira Street, 590, Belo Horizonte, MG, CEP 30150-240, Brazil
| | - Alessandra Hubner de Souza
- Graduate Program in Cellular and Molecular Biology Applied to Health Sciences, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
- Graduate Program in Genetics and Applied Toxicology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
- Department of Pharmacology, Lutheran University of Brazil (ULBRA), Farroupilha Avenue, 8001, Canoas, RS, CEP 92425-900, Brazil
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Vidal-Torres A, Fernández-Pastor B, Carceller A, Vela JM, Merlos M, Zamanillo D. Supraspinal and Peripheral, but Not Intrathecal, σ 1R Blockade by S1RA Enhances Morphine Antinociception. Front Pharmacol 2019; 10:422. [PMID: 31068818 PMCID: PMC6491787 DOI: 10.3389/fphar.2019.00422] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/03/2019] [Indexed: 12/26/2022] Open
Abstract
Sigma-1 receptor (σ1R) antagonism increases the effects of morphine on acute nociceptive pain. S1RA (E-52862) is a selective σ1R antagonist widely used to study the role of σ1Rs. S1RA alone exerted antinociceptive effect in the formalin test in rats and increased noradrenaline levels in the spinal cord, thus accounting for its antinociceptive effect. Conversely, while systemic S1RA failed to elicit antinociceptive effect by itself in the tail-flick test in mice, it did potentiate the antinociceptive effect of opioids in this acute pain model. The present study aimed to investigate the site of action and the involvement of spinal noradrenaline on the potentiation of opioid antinociception by S1RA on acute thermal nociception using the tail-flick test in rats. Local administration was performed after intrathecal catheterization or intracerebroventricular and rostroventral medullar (RVM) cannulae implantation. Noradrenaline levels in the spinal cord were evaluated using the concentric microdialysis technique in awake, freely-moving rats. Systemic or supraspinal administration of S1RA alone, while having no effect on antinociception, enhanced the effect of morphine in rats. However, spinal S1RA administration did not potentiate the antinociceptive effect of morphine. Additionally, the peripherally restricted opioid agonist loperamide was devoid of antinociceptive effect but produced antinociception when combined with S1RA. Neurochemical studies revealed that noradrenaline levels in the dorsal horn of the spinal cord were not increased at doses exerting potentiation of the antinociceptive effect of the opioid. In conclusion, the site of action of σ1R for opioid modulation on acute thermal nociception is located at the peripheral and supraspinal levels, and the opioid-potentiating effect is independent of the spinal noradrenaline increase produced by S1RA.
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Affiliation(s)
- Alba Vidal-Torres
- Drug Discovery and Preclinical Development, Esteve Pharmaceuticals, Parc Científic Barcelona, Barcelona, Spain
| | - Begoña Fernández-Pastor
- Drug Discovery and Preclinical Development, Esteve Pharmaceuticals, Parc Científic Barcelona, Barcelona, Spain
| | - Alicia Carceller
- Drug Discovery and Preclinical Development, Esteve Pharmaceuticals, Parc Científic Barcelona, Barcelona, Spain
| | - José Miguel Vela
- Drug Discovery and Preclinical Development, Esteve Pharmaceuticals, Parc Científic Barcelona, Barcelona, Spain
| | - Manuel Merlos
- Drug Discovery and Preclinical Development, Esteve Pharmaceuticals, Parc Científic Barcelona, Barcelona, Spain
| | - Daniel Zamanillo
- Drug Discovery and Preclinical Development, Esteve Pharmaceuticals, Parc Científic Barcelona, Barcelona, Spain
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Su TP, Su TC, Nakamura Y, Tsai SY. The Sigma-1 Receptor as a Pluripotent Modulator in Living Systems. Trends Pharmacol Sci 2016; 37:262-278. [PMID: 26869505 PMCID: PMC4811735 DOI: 10.1016/j.tips.2016.01.003] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 01/03/2016] [Accepted: 01/05/2016] [Indexed: 01/21/2023]
Abstract
The sigma-1 receptor (Sig-1R) is an endoplasmic reticulum (ER) protein that resides specifically in the mitochondria-associated endoplasmic reticulum (ER) membrane (MAM), an interface between ER and mitochondria. In addition to being able to translocate to the plasma membrane (PM) to interact with ion channels and other receptors, Sig-1R also occurs at the nuclear envelope, where it recruits chromatin-remodeling factors to affect the transcription of genes. Sig-1Rs have also been reported to interact with other membranous or soluble proteins at other loci, including the cytosol, and to be involved in several central nervous system (CNS) diseases. Here, we propose that Sig-1R is a pluripotent modulator with resultant multiple functional manifestations in living systems.
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Affiliation(s)
- Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA.
| | - Tzu-Chieh Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA
| | - Yoki Nakamura
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA
| | - Shang-Yi Tsai
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Baltimore, MD 21224, USA
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7
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Tomohisa M, Junpei O, Aki M, Masato H, Mika F, Kazumi Y, Teruo H, Tsutomu S. Possible involvement of the Sigma-1 receptor chaperone in chemotherapeutic-induced neuropathic pain. Synapse 2015; 69:526-32. [PMID: 26234785 DOI: 10.1002/syn.21844] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 05/22/2015] [Accepted: 06/24/2015] [Indexed: 12/28/2022]
Abstract
Previous studies have shown that ligands of the sigma-1 receptor chaperone (Sig-1R) regulate pain-related behaviors. Clinical use of chemotherapeutics is often compromised due to their adverse side effects, particularly those related to neuropathy. Previous studies have shown that repeated administration of oxaliplatin and paclitaxel produces neuropathy in rodents. Therefore, the aim of the present study was to clarify the involvement of the Sig-1R in chemotherapeutic-induced neuropathy by examining the effects of oxaliplatin and paclitaxel on the Sig-1R levels in the spinal cord, and by examining the effects of Sig-1R agonist and antagonist on oxaliplatin- and paclitaxel-induced neuropathy in rats. Chemotherapeutic-induced neuropathic pain was accompanied by a significant reduction of the Sig-1R level in the spinal cord. Furthermore, the administration of paclitaxel to CHO cells that stably overexpressed Sig-1Rs induced the clustering of Sig-1Rs. We also found that the Sig-1R agonist SA4503 potently inhibited the neuropathy induced by oxaliplatin- and paclitaxel, whereas this action was abolished by the Sig-1R antagonist NE-100. These results suggest that the reduction of Sig-1R activity is involved in chemotherapeutic-induced neuropathy, and the Sig-1R agonist SA4503 could serve as a potential candidate for the treatment of chemotherapeutic-induced neuropathy.
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Affiliation(s)
- Mori Tomohisa
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Ohya Junpei
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Masumoto Aki
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Harumiya Masato
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Fukase Mika
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Yoshizawa Kazumi
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | | | - Suzuki Tsutomu
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
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Mori T, Ohya J, Itoh T, Ise Y, Shibasaki M, Suzuki T. Effects of (+)-pentazocine on the antinociceptive effects of (-)-pentazocine in mice. Synapse 2015; 69:166-71. [DOI: 10.1002/syn.21799] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/20/2014] [Accepted: 11/27/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Tomohisa Mori
- Department of Toxicology; Hoshi University School of Pharmacy and Pharmaceutical Sciences; Tokyo Japan
| | - Junpei Ohya
- Department of Toxicology; Hoshi University School of Pharmacy and Pharmaceutical Sciences; Tokyo Japan
| | - Toshimasa Itoh
- Department of Toxicology; Hoshi University School of Pharmacy and Pharmaceutical Sciences; Tokyo Japan
| | - Yuya Ise
- Department of Toxicology; Hoshi University School of Pharmacy and Pharmaceutical Sciences; Tokyo Japan
| | - Masahiro Shibasaki
- Department of Toxicology; Hoshi University School of Pharmacy and Pharmaceutical Sciences; Tokyo Japan
| | - Tsutomu Suzuki
- Department of Toxicology; Hoshi University School of Pharmacy and Pharmaceutical Sciences; Tokyo Japan
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Bangaru ML, Weihrauch D, Tang QB, Zoga V, Hogan Q, Wu HE. Sigma-1 receptor expression in sensory neurons and the effect of painful peripheral nerve injury. Mol Pain 2013; 9:47. [PMID: 24015960 PMCID: PMC3847629 DOI: 10.1186/1744-8069-9-47] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 09/07/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The sigma-1 receptor (σ1R), an endoplasmic reticulum chaperone protein, is widely distributed and regulates numerous intracellular processes in neurons. Nerve injury alters the structure and function of axotomized dorsal root ganglion (DRG) neurons, contributing to the development of pain. The σ1R is enriched in the spinal cord and modulates pain after peripheral nerve injury. However, σ1R expression in the DRG has not been studied. We therefore characterized σ1R expression in DRGs at baseline and following spinal nerve ligation (SNL) in rats. RESULTS Immunohistochemical (IHC) studies in DRG sections show σ1R in both neuronal somata and satellite glial cells. The punctate distribution of σ1R in the neuronal cytoplasm suggests expression in the endoplasmic reticulum. When classified by neuronal size, large neurons (>1300 μm) showed higher levels of σ1R staining than other groups (700-1300 μm, <700 μm). Comparing σ1R expression in neuronal groups characterized by expression of calcitonin gene-related peptide (CGRP), isolectin-B4 (IB4) and neurofilament-200 (NF-200), we found σ1R expression in all three neuronal subpopulations, with highest levels of σ1R expression in the NF-200 group. After SNL, lysates from L5 DRGs that contains axotomized neurons showed decreased σ1R protein but unaffected transcript level, compared with Control DRGs. IHC images also showed decreased σ1R protein expression, in SNL L5 DRGs, and to a lesser extent in the neighboring SNL L4 DRGs. Neurons labeled by CGRP and NF-200 showed decreased σ1R expression in L5 and, to a lesser extent, L4 DRGs. In IB4-labeled neurons, σ1R expression decreased only in axotomized L5 DRGs. Satellite cells also showed decreased σ1R expression in L5 DRGs after SNL. CONCLUSIONS Our data show that σ1R is present in both sensory neurons and satellite cells in rat DRGs. Expression of σ1R is down-regulated in axotomized neurons as well as in their accompanying satellite glial cells, while neighboring uninjured neurons show a lesser down-regulation. Therefore, elevated σ1R expression in neuropathic pain is not an explanation for pain relief after σ1R blockade. This implies that increased levels of endogenous σ1R agonists may play a role, and diminished neuroprotection from loss of glial σ1R may be a contributing factor.
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Affiliation(s)
- Madhavi L Bangaru
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Dorothee Weihrauch
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Qing-Bo Tang
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Vasiliki Zoga
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Quinn Hogan
- Zablocki Veterans Administration Medical Center, Milwaukee, WI, USA
| | - Hsiang-en Wu
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Abstract
This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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